Carbon Spaser Could Zap Cancer Cells

MELBOURNE, Australia, April 21, 2014 — A carbon-based nanolaser could be used to zap cancer cells, or enable electronics small and flexible enough to be printed on clothing.

Said to be the first of its kind, the spaser – short for surface plasmon amplification by stimulated emission of radiation – was modeled by researchers from Monash University’s Department of Electrical and Computer Systems Engineering. It involves excitons from an optically excited carbon-nanotube gain element interacting with surface plasmons on a graphene nanoflake resonator.

Model of a carbon-based spaser. Courtesy of Monash University.
The spaser would generate high-intensity, nanoscale electrical fields much stronger than those generated by illuminating metal nanoparticles with lasers, said doctoral candidate Chanaka Rupasinghe, and have applications in cancer therapy, among others.

“Scientists have already found ways to guide nanoparticles close to cancer cells,” Rupasinghe said. “We can move graphene and carbon nanotubes following those techniques, and use the [highly concentrated] fields generated through the spasing phenomena to destroy individual cancer cells without harming the healthy cells in the body.”

The researchers derived, in theory, the optimal geometric and material parameters to yield the highest plasmon generation rate. They chose carbon nanostructures because they are more than 100 times stronger than steel, can conduct heat and electricity better than copper, and can withstand high temperatures. These properties make them preferable to other spasers designed with gold or silver nanoparticles, or semiconductor quantum dots, Rupasinghe said.

“Because of these properties, there is the possibility that in the future an extremely thin mobile phone could be printed on clothing,” he said.